A047168 Number of nonempty subsets of {1,2,...,n} in which exactly 4/5 of the elements are <= n/2.

0, 0, 0, 0, 0, 0, 0, 4, 5, 25, 30, 90, 105, 245, 280, 588, 666, 1458, 1665, 4125, 4785, 12705, 14850, 38830, 45331, 113399, 131859, 320411, 371735, 903175, 1048840, 2594540, 3021240, 7594920